(a) Technical Field of the Invention
The present invention generally relates to handbrakes, and more specifically to the structure of a handbrake operating device for improving handbrake sensitivity.
(b) Description of the Prior Art
Conventionally, bicycles, motorcycles, kick scooters, and electric scooters all require a handbrake operating device mounted on the handlebar for stopping the vehicles. The design of the handbrake operating device is therefore a key to the rider's safety.
FIG. 2 is a plan view of a conventional handbrake operating device. As illustrated, the handbrake operating device contains an operating lever and a positioning seat for attaching the handbrake operating device to the handlebar. The positioning seat has a tubular portion so that the handlebar could be fitted inside. The tubular portion is fixed and locked to the handlebar by a pin-jointed member. On the other side of the positioning seat, there is a joining portion opposite to the tubular portion. The joining portion has a through hole whose axial direction is paralleled with the handlebar. The through hole is bolted by a nut having a slot opening. The brake wire is then slid through the slot opening and the through hole, and has its wire head locked in an anchoring hole of the operating lever.
As shown in FIG. 2, the through hole through which the brake wire is slid is designed to be parallel to the handlebar and perpendicular to the positioning seat. In this way, when the operating lever is squeezed inward towards the handlebar, the brake wire is pulled, which in turn leads to the brake devices at the two sides of the wheel to stop the wheel.
Please refer to FIG. 1 again. The handlebar as illustrated has a U shape. When the aforementioned handbrake operating devices are installed on the U-shaped handlebar, the brake wires first go from the joining portion of the positioning seat, horizontally through the slot opening and the through hole, then along the two slant arms of the U-shaped handlebar in an almost vertical angle, and finally down to the bicycle frame to connect with the brake devices.
The brake wire changes its direction from a horizontal one (i.e., parallel to the handlebar) at the joining portion of the positioning seat to a vertical direction (i.e., perpendicular to the handlebar) as it goes down to connect the brake device. Such an abrupt angle would degrade the brake device's responsiveness, which increases the risk of the bicycle rider.
To overcome such a shortcoming, conventionally, the handbrake operating device is moved forward or backward a bit along the handlebar, so as to avoid the vertical section of the handlebar. In this way, the brake wire would undergo a smoother directional change and the handbrake sensitivity is thereby enhanced.
However, adjusting the handbrake operating device's position makes the rider's operation of the handbrake more difficult, as the rider has to reach out for the handbrake operating device. Obviously, there is still plenty of room left for better solutions.